Taking Beijing Language and Culture University (BLCU) as an example, this study analyzed the textbooks in Teaching Chinese as a Second Language (TCSOL) by text analysis, conducted questionnaires and in-depth interviews with TCSOL students, and constructed a framework for future TCSOL teachers’ understanding of ECE based on grounded theory. The research explores the status quo of Ecological Civilization Education (ECE) in TCSOL, TCSOL students’ understanding of ECE, and their perspectives on the integration’s necessity, challenges, and future integration. The findings reveal that while there is a general awareness of ECE among TCSOL students, their understanding is predominantly centered on environmental protection, with limited recognition of its economic and social dimensions. The study also identifies a significant gap in the coverage of Sustainable Development Goals (SDGs) within TCSOL materials, particularly in environmental content. For future integration, students expressed a desire for ECE integration that is less politically focused and more diverse in pedagogical approaches, emphasizing self-exploration and practical applications. Aiming to provide theoretical support for the integration of ECE into TCSOL, this study contributes to global ecological governance and sustainable development in alignment with the United Nations’ 2030 Agenda.